Current concern with and proliferation of day care centers raise serious questions regarding the mental health implications of this total child service. In an effort to clarify relationships between programs of centers, physical design and resultant patterns of facility utilization, the present research will consider two broad areas: 1) a series of comparative studies of two day care centers in the same neighborhood differing in physical form. The objective of these longitudinal observations using behavioral mapping and interviews will be consideration of a) factors related to use patterns with an emphasis on attitudes of occupants, nature of the environment and the day care program; b) change and stability of facility utilization patterns as they develop over time. 2) the development of a format for a continuous planning and evaluation process. Using a third day care center, in the process of being set up, a long-range collaborative process will be instituted involving parents, staff, children, architects and environmental psychologists. The goal will be planning for initial design of the center, evaluation of space use patterns over time and planned changes in design and program when necessary.